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Pulpal considerations

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    Pulpal considerations Pulpal considerations Presentation Transcript

    • Pardis TarighiPULPAL CONSIDERATIONS
    • ADHESIVE SEALERS e.g: adhesive bonding systems-resin luting cements-GI luting cement Pardis Tarighi Provide chemical bond Varnishes reduce but don’t eliminate microleakage around amalgam High copper amalgam Comparable in short term(24hrs to 14days) Leakage increase: margin on dentin/cementum- 1month to year (long term=caries) Drawbacks: pooling of resin(x-ray artifact/perio prob)-incorporation to amalgam/loss of strength- more tech sensitive than varnish
    • PHYSIOLOGIC CONSIDERATIONS 0.5mm=75%1-RDT: 1mm=90% No material provides better protection 2mm 0.25-0.3 Pardis Tarighi Role :Buffering-insulation Single most important factor inprotecting pulp Conservation better than replacement2-Causes of pulpal inflammation: Bacteria or toxins (dental materials : mild &transitory) Early enamel caries ¼ DEJ causes slight reaction (enamel permeability) Outward flow doesn’t prevent bacteria Acid etch: tolerable if bacterial invasion in prevented Rotary instruments : friction/dessication
    • INSTRUMENTATION Least effect: high speed-light force(1-3oz)-new bur- air coolant-water spray-least prep. Pardis Tarighi Frictional heat: burn lesions-abscess Dessication: tolerable in limited areas- loss of dentinal fluid Temperature rise: enamel vs dentine?/ pressure vs speed (low speeds)/ diamond vs carbide bur/ depth of prep.> full coverage:3-22% New methods: laser(co2-Er:YAG-Nd:YAG-FEL)/ air abrasion (water coolant necessary) Electrosurgery: intact enamel/ 0.4sec
    • CAUSES OF PULPAL PAIN inflammation>pressure on nerve ends Pardis Tarighi No inflammation> changes in outward flow speed>deformation of nerve ends
    • CAUSES OF THERMAL SENSITIVITY Theory of thermal shock (diffusivity) >base fore metallic restorations-thickness :0.5-0.75mm-E.M) Pardis Tarighi Theory of pulpal hydrodynamics (gap-volume and flow of outward fluid due to density/diameter/permeability) > effective sealing- integrity of interface 6months max even with no base 50% 24hrs/78% mild almost always disappears within 30 days
    • CAVITY SEALERS,LINERS AND BASES • prevention of leakage at interface- coating all walls : a-varnish (natural/synthetic) b-adhesive sealer Pardis TarighiSealer (seal&bond) • minimal thickness- only near pulp wall- physical barrier and/or therapeutic effect(fluoride-antibacter)Liner • replace missing dentin or block out undercutsBase
    • CAVITY SEALERS Kidd : microleakage= passage of bacteria-fluids- Pardis Tarighi molecules-ions along the interface Leads to : secondary caries-marginal discoloration- pulpal pathosis Causes of clinical failures of restorations : sec. caries- marginal gap/fracture- discoloration
    • VARNISHES Natural gum (copal) , a rosin or synthetic resin dissolved in acetone,chloroform,ether Pardis Tarighi A thin protective film of 2-5μ No thermal insulation 2applications Reducing dentin permeability by 69% Reducing microleakage 4-6months Under ZPC crown cementation
    • LINERS Ca(OH)2 Not all formulations have stimulatory effect on Pardis Tarighi pulpoblasts Reparative dentin assisted rather than stimulated Antibacterial/anti inflammatory action- release G.F from dentin>healing Conventional: poor physical properties-high solubility-lower E.M Light activated : better properties
    • LINERS Glass ionomero Chemical bond-fluoride release Pardis Tarighio Decreases interfacial bacterial penetration (fluoride- low pH- metal cation)o Acidic for 24hrso Conventional : reduced gap-higher E.M-lower resistance to acid etcho Bonded base technique (open sandwich provides better seal due to increased strain capacity because of delayed set)
    • BASES Pardis Tarighi ZOE-ZPC: excellent thermal insulation-physical properties but not adhesive GI (conventional)
    • GUIDELINES FOR BASING-LINING-SEALING Don’t remove sound tooth structure to provide space for base Pardis Tarighi Bases for buildup materials but for if for amalgam or composite restorations: minimal extent Min. thickness of liner Adhesive sealer under amalgam?
    • PULP CAPPING Endodontic treatment designed to maintain the vitality of the endodontium Pardis Tarighi 1-vital pulp/no spontaneous pain 2-no lingering pain after hot/cold stimulus 3-no PA lesion 4-bacteria excluded Indirect P.C prefered Monitoring for several months
    • DIRECT PULP CAP Ideal condition= bacteria free Pardis Tarighi Aged pulps : increased fibrosis and decreased blood supply Type/extent of exposure-bleeding amount Only when: small mechanical exposure of healthy pulp-rubber dam isolation and adequate hemostasis
    • INDIRECT PULP CAP X-ray deep caries-no spontaneous pain-normal vitality test Pardis Tarighi Spoon excavator or large round bur,low speed handpiece Wet(soft,amorphus) dentin removed- dry, fibrous demineralized dentin leaved(moderate resistance to gentle scraping) Caries-disclosing dyes: caution for deep dentin Delay indirect restorations 4-6months Do not remove IPC after removing temporary restoration
    • DENTIN BONDING VS CA(OH)2 AS DPC After smear layer removal pulpal tissue and adhesive resin are compatible for 90days Faster dentin bridge with Ca(OH)2 Toxic components rapid release Pardis Tarighi In bacteria free environment>successful capping with bonding Imperfect seal (nanoleakage in hybrid layer-collagen hydrolysis) Lower bond strength to carious dentin Less intertubular dentin in deep lesions Bond degredation Acid etch: increase dentinal fluid flow-foreign body reaction- increased bleeding Resin components inhibit T lymphocytes QTH temperature(20sec=25.2˚c)/11.2 irreversible damage
    • CALCIUM HYDROXIDE SHORTCOMINGS Break down in acid etching Pardis Tarighi Dissolution under leaking restoration Interfacial failure in amalgam condensation Tunnel defect in reparative dentin
    • FUTURE OF DIRECT PULP CAPPING MATERIALS Hydroxyapatite as scaffold for dentin formation Pardis Tarighi BMP-BSP MTA(tricalcium silicate/aluminate/oxide-silicate oxide) : high pH- compressive strength comparable to reinforced ZOE-radiopaque-antibacterial- biocompatible
    • ANTIBACTERIAL EFFICACY OF RESTORATIVEMATERIALS Amalgam: copper-mercury-zinc-silver-chloride components/effective against: S mutans, A Pardis Tarighi viscous, lactobacillus spp Marginal seal improves with time(acidic environment/ low oxygen concentration/corrosion products) GI Resin composites (some resin components/Glutaraldehyde)